In some places, property tax is pinned to the purchase price. This is the case in the bay area. If you bought for 60k, then your taxes are based on 60k.

This is also what makes these "values" absurd. Yes, on paper it's worth that. Can you sell it for that? Probably not because the new owner's taxes will factor into their offer (since the sales price dictates the new tax basis) and it's likely much harder to sell.